netfilter: ip6t_SYNPROXY: fix NULL pointer dereference

This happens when networking namespaces are enabled.

Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 file changed